16 Čen
2015
16 Čen
'15
0:20
On Jun 15, 2015, at 1:43 PM, Ondřej Surý
<ondrej.sury(a)nic.cz> wrote:
Hi Charles,
this is hard to say without a specific example, but generally the Knot DNS is trying to
send minimal usable response that doesn't include resource records that won't be
used by modern resolvers.
The modern resolvers generally throw away any records that are not within very strict
bailiwick (e.g. anything extra that resolver hasn't asked for will be discarded). If
you can give us an example of such responses we can decode why the records won't be
used by resolvers (or whether it is really bug in Knot DNS).
The specific information that BIND returns is a list of A records that list our name
servers and their IP addresses. I'm not sure how it decides to send this particular
information, but it does. It has a set of config directives that control generally whether
additional information is sent.
It may be that we don't want to send additional information. At least one person on
the BIND mailing list expressed opinions similar to what you're saying: authoritative
servers should only respond with what was requested (and not send additional data). If
that data is sent for every request and not used, then that's wasteful.
Chuck